The present invention relates to a new and distinctive variety of apple tree belonging to a medium-maturing apple cultivar and, more particularly, relates to an apple variety having high quality and high resistance to disease and insect, for eating raw and for processing.
Regarding medium-maturing apple varieties, although xe2x80x98Jonathanxe2x80x99 and xe2x80x98Starking Deliciousxe2x80x99 were widely cultivated in the past, they have become unpopular due to their taste and poor storage quality, and there are no main medium-maturing apple varieties now known to us. Thus it was necessary to breed a main medium-maturing apple variety immediately.
Accordingly, the present breeders crossed xe2x80x98Hatsuakixe2x80x99, which is an excellent variety for both eating raw and for processing, with xe2x80x98Fujixe2x80x99, which is a main economical variety, to obtain excellent medium-maturing apple varieties having good fruit quality and high productivity. Namely, the purpose of the invention is to avoid russet on fruit surface and to improve the storage quality of the medium-maturing variety xe2x80x98Hatsuakixe2x80x99 and to breed a new and distinct variety of medium-maturing apple variety having excellent disease and insect resistance for eating raw and for processing.
To accomplish this purpose, the breeders crossed xe2x80x98Fujixe2x80x99, which had been cultivated at the Morioka branch of the Fruit Tree Research Station (currently the Apple Research Center, the National Institute of Fruit Tree Science), in Japan, and xe2x80x98Hatsuakixe2x80x99 in 1976 and obtained seeds. The seeds obtained were utilized for sowing and raising seedlings at said branch, in 1977, and the resulting seedlings were then grafted on xe2x80x98M27xe2x80x99, the most dwarfing rootstock, to accelerate bearing in 1978, and 127 individuals were set in 1980.
The trees bore fruit in 1984 and one was selected in the primary selection as a good medium-maturing individual in 1986. The present invention is directed to an apple tree xe2x80x98Kitaroxe2x80x99, which is one individual from among the 127 individuals derived from the cross xe2x80x98Fujixe2x80x99 (♀) (the seed parent) and xe2x80x98Hatsuakixe2x80x99 (♂) (the pollen parent), and was given an individual number xe2x80x9c512xe2x80x9d during testing. Then the tree was selected as a favorable line of trees, which have a line name Ringo Morioka 52 Go, have been provided for local adaptability tests since 1991, and were examined to determine the various characteristics thereof, over a period of eight years from April 1989 to March 1997. As a result, it was found that, for example, fruit of the trees had the desired characteristics, such as quality, storage quality and yield, as a medium-maturing apple variety, and the tree was distinguishable from the parent varieties, xe2x80x98Fujixe2x80x99 and xe2x80x98Hatsuakixe2x80x99, as well as a control variety xe2x80x98Golden Deliciousxe2x80x99. Accordingly, the breeders denominated this variety as xe2x80x98Kitaroxe2x80x99, in accordance with this invention. The genus and species of the tree is xe2x80x98Malusxc3x97domesticaxe2x80x99. 
Of the varieties, xe2x80x98Fujixe2x80x99 is a variety generated from a cross between xe2x80x98Ralls Janetxe2x80x99 and xe2x80x98Deliciousxe2x80x99.
Of the varieties, xe2x80x98Hatsuakixe2x80x99 is a variety generated from a cross between xe2x80x98Jonathanxe2x80x99 and xe2x80x98Golden Deliciousxe2x80x99.
The breeders asexually reproduced this new and distinctive variety of apple tree xe2x80x98Kitaroxe2x80x99, by grafting on rootstock xe2x80x98M.27xe2x80x99 (U.S. Plant Pat. No. 3,793), at a number of Fruit Tree Research Stations in Morioka City, Iwate prefecture, Japan, and confirmed the homogeneity and stability of xe2x80x98Kitaroxe2x80x99 according to the present invention. The instant plant retains its distinctive characteristics and reproduces true to type in successive generations.
Of the above varieties, only M.27 is known to us as having been patented in the United States.
An application for this new variety of apple tree, xe2x80x98Kitaroxe2x80x99 under the Seeds and Seedlings Law of Japan, was filed on Apr. 11, 1997, under the filing number 9766.
The original tree of this apple tree is held at the Apple Research Center of the National Institute of Fruit Tree Science, Ministry of Agriculture, Forestry and Fisheries, residing at 92 Nabeyashiki, Shimokuriyagawa, Morioka City, Japan.
This new variety of apple tree, having medium vigor, is spreading, and many spurs and axillary buds are formed.
The leaves of the tree are elliptic and serrated.
At Morioka City, Iwate prefecture, Japan, the trees have a flowering time around May 21th. As the type of S gene of the present variety is (S3, S9), the cross-compatibility with common cultivars except xe2x80x98Hatsuakixe2x80x99 and xe2x80x98Sekaiichixe2x80x99 is high.
There is slightly heavy preharvest drop of fruit and the present variety exhibits high productivity. Regarding the main diseases, the tree is resistant to Alternaria blotch, but is susceptible to scab. It has not been recognized so far that any disease or insect except for the above, is significant.
The ripening of the present fruit occurs in mid October at Morioka, later by about one week than xe2x80x98Senshuxe2x80x99, and earlier by one week than xe2x80x98Golden Deliciousxe2x80x99. The size of the fruit is medium and averages about 250-270 g, the same as xe2x80x98Senshuxe2x80x99. Although the type of ground color of the skin of the fruit is yellow (6D by RHS) and that of the over-color is red-purple (63C by RHS), the surface of the skin, receiving sunlight is colored with dull pink. The shape of the fruit is oblate and the amount of the russet on the skin is high, thus the appearance of the fruit is not good. Depending on the years, cracking occurs in the stalk cavity of the fruit.
The flesh of the present fruit contains much sugar, about 15-16% Brix of the total sugar, and about 0.5 g/100 ml of malic acid, and further the flesh is firm and juicy, has a strong sweetness and medium sourness and provides a good sweet-sour balance and rich taste. The storage quality of the fruit is excellent, and is about 15 days at room condition and more than 90 days in cold storage.
Compared with the seed parent, xe2x80x98Fujixe2x80x99, the present variety is distinguishable in that ripening of the fruit is earlier by about 20 days than that of xe2x80x98Fujixe2x80x99, the type of over color of the skin of the present variety is yellow, whereas that of xe2x80x98Fujixe2x80x99 is colored with deep-reddish stripe, and the fruit of the present variety does not have tendency to an inclination of the axis, as does xe2x80x98Fujixe2x80x99.
Compared with the pollen parent, xe2x80x98Hatsuakixe2x80x99, the present variety is distinguishable in that flowering is earlier by several days and the ripening of the fruit is later by about 10-15 days than that of xe2x80x98Hatsuakixe2x80x99, the color of the skin is yellow, whereas that of xe2x80x98Hatsuakixe2x80x99 is reddish-orange, and the flesh of the present variety is firm, and the storage quality is excellent.
Compared with xe2x80x98Golden Deliciousxe2x80x99, the present variety is clearly distinguishable in that the ripening of the fruit is earlier by about one week, and there is preharvest drop of the fruit, the shape of the fruit is flatter than that of xe2x80x98Golden Deliciousxe2x80x99, the flesh is firm and the storage quality is excellent.
The color references presented are herein taken from The Royal Horticultural Society Color Chart (R.H.S.) except where general terms of ordinary significance are used.